This invention relates to corner mounts for sheet-like articles such as photographs, and methods for making and using such corner mounts.
Corner mounts, by which a photograph, card or other sheet may be mounted to a surface, have been in use for decades. U.S. Pat. No. 1,742,615, dated Jan. 7, 1930 (Riley), describes a configuration for a paper corner mount and a process for its manufacture that still are in use today. U.S. Pat. No. 1,355,694, issued Oct. 12, 1920 (Riley) describes an earlier paper corner mount. Each of the Riley patents describes a corner mount in which a paper blank is formed to have selected marginal or corner portions that are folded over to form a pocket receptive to a corner of a photograph or the like. The folded-over margins are retained in the pocket configuration either by selective placement of adhesive or by a second sheet or xe2x80x9ccapxe2x80x9d that overlies and is adhesively attached to the exposed surfaces of the folded over margins. The underside of the mounting corner is coated with a water-based gum adhesive. The portions of the corner mount that form the pocket typically are embossed to form out-of-plane ridges that project from the inner surface of the cap into the pocket. The ridges are arranged so that when the corner of a photograph or card is inserted into the pocket, they will engage the corner sufficiently to hold itself onto the corner of the photograph as the photograph is manipulated into position on the mounting surface. That permits the corner mounts to be placed on all the corners of the photograph before any of the gummed bottom surfaces are moistened. Thus all of the gummed bottom surfaces may be moistened at about the same time and promptly applied, together, in the correct relative position to the surface to which the photograph is to be mounted.
It has been recognized that it would be more convenient to provide a corner mount that used a self-stick adhesive that did not require moistening in order to activate the adhesive. To that end, mounting corners have been made, and are commercially available, in which the corner is coated on its underside with a pressure sensitive adhesive that is covered by a peelable layer from which the mounting corner is removed in order to expose the adhesive. Such mounting corners, however, are made from plastic sheets or films. Such plastic corner mounts are considered to compromise the advantages of paper corner mounts in order to avoid the necessity of moistening the corner mounts before applying them to the mounting surface. Among the disadvantages of corner mounts formed from plastic is that they do not lend themselves to embossing to form projections or ridges that project into the pocket. Consequently, they do not grip the corner of the photograph as well as embossed paper corners. Moreover, the embossed pattern also provides somewhat of an aesthetic appearance which is not readily duplicated with a plastic device. Additionally, plastic corner mounts are believed to be formed using heat sealing techniques and may not have the archival qualities that are achievable with paper construction.
It would be desirable to provide self-sticking paper mounting corners and methods for their manufacture.
The invention enables manufacture of paper corner mounts using printing machinery capable of adhesively joining layers of paper and then selectively cutting the sandwiched web to leave a group of corner mounts that are releasably and individually attached, by a pressure sensitive adhesive, to a supporting release liner. The arrangement enables a corner mount to be detached by inserting the corner of a photograph or the like into the pocket of a corner mount on the release liner and then manipulating the photograph to separate the corner mount from the release layer. The layer of pressure sensitive adhesive remains with the detached corner mount so that the photograph, together with the corner mounts simply can be pressed against the page or other support surface to which the corner mounts are to be attached. By forming the corner mounts from paper they are embossed easily during the manufacturing process to provide a decorative, aesthetic appearance and corner-gripping projections, as well as to enable the manufacture of an archival product. The construction of the corner mounts embodying the invention enables them to be made economically on high speed web printing machinery, such as flexographic label printers.